I played that demo but cannot remember the name.. it was intresting but. I will see if i can dig though my old downloads and find it.. it was not X3 though..
it is alot like a wing commander title that was out awhile ago.. you can fly between planets, get jobs, haul cargo, all while following a storyline if you choose to.. why was your father killed.. you get a nifty space craft that can be customized by adding some rare gems that will add more abilities to your craft. think your craft could also change shape to a degree depening ont he modification route you chose.
That game is DarkStar One . . . a "pretty" game . . . but you can get bored with it within an hour or two . . . same thing over and over . . . fight pirates, get reward, upgrade ship . . . rince and repeat
X3 is a nice game as well but after about 50 hours it does get old as well . . . but at least X3 does have some aspects that change from time to time . . . not the same thing over and over